Denver Broncos weakside linebacker Danny Trevathan was carted off the field with a knee injury at practice Wednesday. There was no immediate word on the severity.
Teammates said Trevathan was hurt toward the end of the workout.
Coach John Fox only mentioned the second-year linebacker in passing when rattling off injuries after practice, saying Trevathan was ''limited, knee.''
Steven Johnson is listed as Trevathan's backup.
The loss of Trevathan would be a big blow to the Broncos (4-0). According to Pro Football Focus, he was the league's top 4-3 outside linebacker against the run in the first month of the season.
He's second on the team with 30 tackles and 24 unassisted tackles and has a sack, an interception and four pass breakups so far.